Smart Chair: What Can Simple Pressure Sensors under the Chairs' Legs Tell Us about User Activity?
Jingyuan Cheng, Bo Zhou, Mathias Sundholm, Paul Lukowicz · Ubiquitous Computing Systems · 2013
In this paper, we investigate how much information about user activity can be extracted from simple pressure sensors mounted under the legs of a chair. We show that it is possible to detect not only different postures (0.826 accuracy for 5 subjects and 7 classes), but also subtle hand and head related actions like typing and nodding (0.880 accuracy for 5 subjects and 5 classes). Combining features related to postures and such simple actions, we can detect high-level activities such as working on a PC, watching a movie or eating in a continuous, real-life data stream. In a dataset of 105.6 hours recorded from 4 subjects, we achieved 0.783 accuracy for 7 classes. Keywords—ubiquitous computing; smart chair; resistive pres- sure sensor; activity recognition